A Caltech Library Service

Late-time Evolution and Modeling of the Off-axis Gamma-Ray Burst Candidate FIRST J141918.9+394036

Mooley, K. P. and Margalit, B. and Law, C. J. and Perley, D. A. and Deller, A. T. and Lazio, T. J. W. and Bietenholz, M. F. and Shimwell, T. and Intema, H. T. and Gaensler, B. M. and Metzger, B. D. and Dong, D. Z. and Hallinan, G. and Ofek, E. O. and Sironi, L. (2022) Late-time Evolution and Modeling of the Off-axis Gamma-Ray Burst Candidate FIRST J141918.9+394036. Astrophysical Journal, 924 (1). Art. No. 16. ISSN 0004-637X. doi:10.3847/1538-4357/ac3330.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present new radio and optical data, including very-long-baseline interferometry, as well as archival data analysis, for the luminous, decades-long radio transient FIRST J141918.9+394036. The radio data reveal a synchrotron self-absorption peak around 0.3 GHz and a radius of around 1.3 mas (0.5 pc) 26 yr post-discovery, indicating a blastwave energy ∼5 × 10⁵⁰ erg. The optical spectrum shows a broad [O iii]λ4959,5007 emission line that may indicate collisional excitation in the host galaxy, but its association with the transient cannot be ruled out. The properties of the host galaxy are suggestive of a massive stellar progenitor that formed at low metallicity. Based on the radio light curve, blastwave velocity, energetics, nature of the host galaxy and transient rates, we find that the properties of J1419+3940 are most consistent with long gamma-ray burst (LGRB) afterglows. Other classes of (optically discovered) stellar explosions as well as neutron star mergers are disfavored, and invoking any exotic scenario may not be necessary. It is therefore likely that J1419+3940 is an off-axis LGRB afterglow (as suggested by Law et al. and Marcote et al.), and under this premise the inverse beaming fraction is found to be f⁻¹_b ≃ 280_₋₂₀₀⁺⁷⁰⁰, corresponding to an average jet half-opening angle <θ> ≃ 5₋₂⁺⁴ degrees (68% confidence), consistent with previous estimates. From the volumetric rate we predict that surveys with the Very Large Array, Australian Square Kilometre Array Pathfinder, and MeerKAT will find a handful of J1419+3940-like events over the coming years.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Mooley, K. P.0000-0002-2557-5180
Margalit, B.0000-0001-8405-2649
Law, C. J.0000-0002-4119-9963
Perley, D. A.0000-0001-8472-1996
Deller, A. T.0000-0001-9434-3837
Lazio, T. J. W.0000-0002-3873-5497
Bietenholz, M. F.0000-0002-0592-4152
Shimwell, T.0000-0001-5648-9069
Intema, H. T.0000-0002-5880-2730
Gaensler, B. M.0000-0002-3382-9558
Metzger, B. D.0000-0002-4670-7509
Dong, D. Z.0000-0001-9584-2531
Hallinan, G.0000-0002-7083-4049
Ofek, E. O.0000-0002-6786-8774
Sironi, L.0000-0002-1227-2754
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 June 27; revised 2021 October 4; accepted 2021 October 24; published 2022 January 6. We thank Chuck Steidel for insights into the origin of the broad emission line in the optical spectrum, and the anonymous referee for comments that helped improve the clarity of the paper. K.P.M. thanks Wenbin Lu for discussions on mass-loss history and off-axis jet, and Anna Ho for discussions on SSA analysis. K.P.M. is a Jansky Fellow of the National Radio Astronomy Observatory. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The NANOGrav project receives support from the National Science Foundation (NSF) Physics Frontiers Center award number 1430284. C.J.L. acknowledges support from the National Science Foundation grant No. 2022546. B.M. is supported by NASA through the NASA Hubble Fellowship grant #HST-HF2-51412.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. K.P.M. and G.H. acknowledge support from the National Science Foundation grant No. AST-1911199. The Dunlap Institute is funded through an endowment established by the David Dunlap family and the University of Toronto. B.M.G. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through grant No. RGPIN-2015-05948, and of the Canada Research Chairs program. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The NANOGrav project receives support from National Science Foundation (NSF) Physics Frontier Center award number 1430284. Facilities: VLA - Very Large Array, VLBA. Software: AIPS, v. 31DEC19 (van Moorsel et al. 1996); CASA, v. 5.5.0-77 (McMullin et al. 2007).
Group:Astronomy Department
Funding AgencyGrant Number
Jansky FellowshipUNSPECIFIED
NASA Hubble FellowshipHST-HF2-51412.001-A
David Dunlap FamilyUNSPECIFIED
University of TorontoUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)RGPIN-2015-05948
Canada Research Chairs ProgramUNSPECIFIED
NASA Einstein FellowshipUNSPECIFIED
Subject Keywords:Radio transient sources; Gamma-ray bursts; Supernovae; Surveys; Magnetars
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Radio transient sources (2008); Gamma-ray bursts (629); Supernovae (1668); Surveys (1671); Magnetars (992)
Record Number:CaltechAUTHORS:20220114-266164000
Persistent URL:
Official Citation:K. P. Mooley et al 2022 ApJ 924 16
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112932
Deposited By: George Porter
Deposited On:18 Jan 2022 16:22
Last Modified:18 Jan 2022 16:22

Repository Staff Only: item control page